Conventionally, there have been techniques for supplying, among electric vehicles (EV) that travel in a platoon, power from a surplus-power vehicle with extra power to a power-shortage vehicle lacking in power. Here, the traveling in a platoon means that vehicles whose destinations are the same or different travel together along a common route. Vehicles may join or leave the platoon during their travel. Furthermore, the surplus-power vehicle with extra power means a vehicle having additional power other than the power necessary to travel up to a predetermined point, whereas the power-shortage vehicle lacking in power means a vehicle that does not have power necessary to travel up to a predetermined point.
Examples of the techniques include a disclosed technique for supplying power from a surplus-power vehicle to a power-shortage vehicle during their travel (see, for example, Patent Document 1). Further disclosed is a technique with which while maintaining power necessary to reach a charging station, a surplus-power vehicle supplies the remaining power to a power-shortage vehicle (see, for example, Patent Document 2). Here, the charging station means a facility that charges power into a battery included in an EV.